Lemma 3 ([1]}) 
Let \((X,d)\)  be a metric space with a finite measure \(\mu \)  such that
every open set is \(\mu \) -measurable. Let \(A\)  be a Borel subset of \(X\) 
and let \(f:\mathbb {R}_{\ge 0}\rightarrow \mathbb {R}_{\ge 0}\)  be an increasing function with \(f(x)\rightarrow 0\)  as
\(x\rightarrow 0\) . If for every open set \(U\subset X\)  we have
\(\mu (A\cap U) \ge f(\mu (U)),\) 
